From owner-svn-src-all@FreeBSD.ORG Mon Sep 21 16:15:22 2009 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EBCA3106566C; Mon, 21 Sep 2009 16:15:22 +0000 (UTC) (envelope-from rmacklem@uoguelph.ca) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 3A4AE8FC1D; Mon, 21 Sep 2009 16:15:21 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApoEAGJDt0qDaFvI/2dsb2JhbADSUYQbBQ X-IronPort-AV: E=Sophos;i="4.44,425,1249272000"; d="scan'208";a="48807458" Received: from darling.cs.uoguelph.ca ([131.104.91.200]) by esa-jnhn-pri.mail.uoguelph.ca with ESMTP; 21 Sep 2009 12:15:19 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by darling.cs.uoguelph.ca (Postfix) with ESMTP id 2C1A2940099; Mon, 21 Sep 2009 12:15:19 -0400 (EDT) X-Virus-Scanned: amavisd-new at darling.cs.uoguelph.ca Received: from darling.cs.uoguelph.ca ([127.0.0.1]) by localhost (darling.cs.uoguelph.ca [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id oZcI5crmkKRd; Mon, 21 Sep 2009 12:15:18 -0400 (EDT) Received: from muncher.cs.uoguelph.ca (muncher.cs.uoguelph.ca [131.104.91.102]) by darling.cs.uoguelph.ca (Postfix) with ESMTP id 21DCA94007B; Mon, 21 Sep 2009 12:15:18 -0400 (EDT) Received: from localhost (rmacklem@localhost) by muncher.cs.uoguelph.ca (8.11.7p3+Sun/8.11.6) with ESMTP id n8LGKuQ10491; Mon, 21 Sep 2009 12:20:56 -0400 (EDT) X-Authentication-Warning: muncher.cs.uoguelph.ca: rmacklem owned process doing -bs Date: Mon, 21 Sep 2009 12:20:56 -0400 (EDT) From: Rick Macklem X-X-Sender: rmacklem@muncher.cs.uoguelph.ca To: "M. Warner Losh" In-Reply-To: <20090920.155347.-675685342.imp@bsdimp.com> Message-ID: References: <4AB495DD.1010006@FreeBSD.org> <20090919.230053.58383965.imp@bsdimp.com> <20090920.155347.-675685342.imp@bsdimp.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: svn-src-head@FreeBSD.org, rmacklem@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org, jhb@FreeBSD.org Subject: Re: svn commit: r197298 - head/sbin/mount_nfs X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Sep 2009 16:15:23 -0000 On Sun, 20 Sep 2009, M. Warner Losh wrote: > : Someone mentioned an issue w.r.t. umount using UDP, which was basically > : a slow timeout when a server didn't handle the UDP call, such as when > : it was down. I'd guess that a TCP attempt would fail more quickly than > : a UDP attempt when the server doesn't have rpcbind/portmapper running. > : (Not so sure when the server has crashed, but I'm guessing that the TCP > : connection attempt fails more quickly than the N retries over UDP?) > > A server down would have the same timeout issues as a UDP timeout. > I was thinking of this email: http://docs.freebsd.org/cgi/getmsg.cgi?fetch=213665+0+archive/2009/freebsd-current/2 Actually, we were both wrong (although you were closer), at least for the little experiment I just tried.:-) When the server is up, but not supporting that protocol (UDP or TCP), both cases failed in < 1sec. (So, you got this one right. I had thought UDP would take longer, but it didn't. It appears that the ICMP Dest Unreachable causes it to fail quickly. I have no idea if ICMP Dest. Unreachable messages get forwarded normally. Maybe that's what the email was alluding to when he said "some situations".) When the server is down/network partitioned, it actually took longer for TCP (1min vs about 10sec) for the defaults in the 8.0 RPC libraries. Probably not relevent to the discussion, but I thought someone might find it interesting, rick